No question is so difficult to answer as that to which the answer is obvious.
-- George Bernard Shaw

A prudent question is one-half of wisdom.
-- Francis Bacon

I am prejudiced in favor of him who, without impudence, can ask boldly. He has faith in humanity, and faith in himself. No one who is not accustomed to giving grandly can ask nobly and with boldness.
-- Johann Kaspar Lavater

By nature's kindly disposition most questions which it is beyond a man's power to answer do not occur to him at all.
-- George Santayana